BANGOR, Maine — The arraignment of Michael “Bub” Tardiff in U.S. District Court on Friday brought to an even dozen the number of people arrested in connection with a bath salts distribution ring that allegedly operated between April 1 and Dec. 31, 2011.

Tardiff, 53, of Old Town pleaded not guilty to one count each of conspiracy to possess with intent to distribute a controlled substance and using or maintaining a drug-involved place at 49 Loonie Loop in Old Town.

Ryan Ellis, 32, formerly of Greenbush and Dover-Foxcroft, also known as “Dude,” “Calvin” or “Piles,” has pleaded not guilty to four counts — conspiracy to possess and distribute a controlled substance, using or maintaining a drug-involved residence in Old Town with Bryden and Tardiff, unlawful use of a controlled substance, and carrying a firearm during and in relation to a drug trafficking offense.

Ellis was living and working in Piscataquis County when he was arrested on the federal charge Aug. 6, according to a previous published report. He was on community release from the Charleston Correctional Facility, serving a three-year state sentence on a drug charge, when he was indicted on the federal charges. He chose to return to the state prison to complete his sentence on the state charge rather than be held without bail on the federal charge.

Alan Ketchen, 40, formerly of Bangor, who is known as “AJ” or “Hobbes,” pleaded not guilty to the drug conspiracy charge and an additional charge of using or maintaining a drug-involved residence at 10 Blackstone St. in Bangor to deal bath salts.

Ketchen will be held without bail on the federal charge until his case is resolved, according to documents filed on the court’s electronic case filing system.

Tina Keaton, 32, of Bangor, also known as “Fumble”; Jamie Lewis, 37, formerly of Bangor, now of New Hampshire; Jacob Gagnon, 24, formerly of Bangor and now of Van Buren, also known as “Jake the Snake”; April Kane, 28, of Gorham; and Gina Nelson, 30, of Bradley have been released on bail. All pleaded not guilty to the drug conspiracy charge.

Daniel Hines, 37, of Orrington and Adam Hathorn, 35, of Bangor are being held without bail on the drug conspiracy charge. Both have pleaded not guilty.

If convicted, defendants charged in the alleged drug conspiracy face up to 20 years in prison and a $2 million fine. In addition, Ellis, Ketchen, Bryden and Tradiff face up to 20 years and fines of up to $500,000 for maintaining drug-involved premises if convicted on that charge.

On the gun charges, Ellis faces up to 10 years and a $250,000 fine for possessing a firearm while using drugs and between five years and life to be served consecutively to any sentence on the conspiracy charge for carrying firearms during and in relation to a drug trafficking crime.